T-Mobile US Inc’s $26 billion acquisition of rival Sprint Corp appeared to win the support of a majority of the Federal Communications Commission on Monday, in a significant step toward the deal’s approval.

FCC Chairman Ajit Pai, a Republican, came out in favor of the combination after the companies offered concessions, including selling Sprint’s Boost Mobile prepaid cell service, as did FCC Commissioner Brendan Carr, a Republican.

The five-member panel’s third Republican, Mike O’Rielly, said he was “inclined to support” the proposed merger, even if he was not convinced of the need for all of the conditions announced by Pai.

If the deal is completed, the number of U.S. wireless carriers would drop to three from four, with Verizon Communications Inc and AT&T Inc leading the pack.

Some telecommunications experts have predicted that prices for cellphone service would rise as a result, and U.S. Senator Richard Blumenthal agreed.

“The FCC’s seeming abdication makes it even more important for the Department of Justice to step up to the plate to block this merger,” the Democratic senator said in a statement.

More at Reuters.